常用内存数据处理函数



//windows_x86




#pragma once


 volatile bool __cdecl _memset(void *_dst, int _val, size_t _nlen);


 volatile bool __cdecl _memxch(void *_dst, void *_src, size_t _nlen);


 volatile bool __cdecl _memxch_s(void *_dst, void *_src, size_t _nlen);


 volatile bool __cdecl _memcpy(void *_dst, const void *_src, size_t _nlen);


 volatile bool __cdecl _memcmp(const void *_dst, const void *_src, size_t _nlen);





#include "stdafx.h"
 #include "almem.h"




 volatile __declspec(naked) bool __cdecl _memset(void *_dst, int _val, size_t _nlen)
 {
	_asm
	{
		push ebp
		mov ebp,esp
		push edi
		mov edi, dword ptr ss : [esp+0x0C]
		cmp edi,0x00
		jz _error
		push ecx
		mov ecx, dword ptr ss : [esp+0x18]
		mov al, byte ptr ss : [esp+0x014]
		rep stos byte ptr es : [edi]
		mov ax,0x01
 	_quit :
		pop ecx
		pop edi
		leave
		ret
	_error :
		mov ax,0x00
		jmp _quit
		nop
		nop
		nop
		nop
	}
}


 volatile __declspec(naked) bool __cdecl _memxch(void *_dst, void *_src, size_t _nlen)
 {
	_asm 
	{
		push ebp
		mov ebp,esp
		mov eax, dword ptr ss : [esp+0x08]
		cmp eax,0x00
		jz _error
		push esi
		mov esi, dword ptr ss : [esp+0x10]
		cmp esi,0x00
		jz _error
		cmp eax,esi
		je _error
		push ebx
		mov ebx, dword ptr ss : [esp+0x18]
		sub esp,ebx
		mov edi,esp
		mov ecx,ebx
		rep movs    //xchg reg,[reg/adr]
		lea edx,dword ptr es : [edi-0x01]
		sub esi,ebx
		mov edi,esi
		mov esi,eax
		mov ecx,ebx
		rep movs
		std
		lea edi,dword ptr es : [esi-0x01]
		mov esi,edx
		mov ecx,ebx
		rep movs
		cld
		add esp,ebx
		mov ax,0x01
 	_quit :
		pop ebx
		pop esi
		leave
		ret
	_error :
		mov ax,0x00
		jmp _quit
		nop
		nop
		nop
		nop
	}
}


 volatile __declspec(naked) bool __cdecl _memxch_s(void *_dst, void *_src, size_t _nlen)
 {
	_asm
	{
		push ebp
		mov ebp,esp
		push edi
		mov edi, dword ptr ss : [esp+0x0C]
		cmp edi,0x00
		je _error
		push esi
		mov esi, dword ptr ss : [esp+0x14]
		cmp esi,0x00
		je _error
		cmp edi,esi
		je _error
		push ecx
		mov ecx, dword ptr ss : [esp+0x1C]
		mov edx,ecx
		shr ecx,0x02
	_next_dword :
		cmp ecx,0x00
		je _next_sing
		mov eax, dword ptr es : [edi]
		mov ebx, dword ptr es : [esi]
		xor eax,ebx
		xor ebx,eax
		mov dword ptr es : [esi], ebx
		xor eax,ebx
		mov dword ptr es : [edi], eax
		add edi,0x04
		add esi,0x04
		dec ecx
		jmp _next_dword
	_next_sing :
		mov ecx,edx
		and ecx,0x03
		jnz _next_byte
	_quit :
		mov ax,0x01
		pop ecx
		pop esi
		pop edi
		leave
		ret
	_next_byte :
		cmp ecx, 0x00
		je _quit
		mov al, byte ptr es : [edi]
		mov bl, byte ptr es : [esi]
		xor al,bl
		xor bl,al
		mov byte ptr es : [esi],bl
		xor al,bl
		mov byte ptr es : [edi],al
		inc edi
		inc esi
		dec ecx
		jmp _next_byte
	_error :
		mov ax,0x00
		pop ecx
		pop esi
		pop edi
		leave
		ret
		nop
		nop
		nop
		nop
	}
}


 volatile __declspec(naked) bool __cdecl _memcpy(void *_dst, const void *_src, size_t _nlen)
 {
	_asm
	{
		push ebp
		mov ebp,esp
		push edi
		mov edi, dword ptr ss : [esp+0x0C]
		cmp edi,0x00
		jz _error
		push esi
		mov esi, dword ptr ss : [esp+0x14]
		cmp esi,0x00
		jz _error
		cmp edi,esi
		je _error
		push ecx
		mov ecx, dword ptr ss : [esp+0x1C]
		mov edx,ecx
		shr ecx,0x02
		rep movs dword ptr es : [edi], dword ptr es : [esi]
		mov ecx,edx
		and ecx,0x03
		je _quit
		rep movs byte ptr es : [edi], byte ptr es : [esi]
	_quit :
		mov ax,0x01
		pop ecx
		pop esi
		pop edi
		leave
		ret
	_error :
		mov ax,0x00
		jmp _quit
		nop
		nop
		nop
		nop
	}
}


 volatile __declspec(naked) bool __cdecl _memcmp(const void *_dst, const void *_src, size_t _nlen)
 {
	_asm
	{
		push ebp
		mov ebp,esp
		push edi
		mov edi, dword ptr ss : [esp+0x0C]
		cmp edi,0x00
		jz _error
		push esi
		mov esi, dword ptr ss : [esp+0x14]
		cmp esi,0x00
		jz _error
		cmp edi,esi
		je _quit
		push ecx
		mov ecx, dword ptr ss : [esp+0x1C]
		mov edx,ecx
		shr ecx,0x02
		repe cmps dword ptr es : [edi], dword ptr es : [esi]
		jne _error
		mov ecx,edx
		and ecx,0x03
		jnz _next_byte
	_quit :
		mov ax,0x01
		pop ecx
		pop esi
		pop edi
		leave
		ret
	_next_byte :
		repe cmps byte ptr es : [edi], byte ptr es : [esi]
		je _quit
	_error :
		mov ax, 0x00
		pop ecx
		pop esi
		pop edi
		leave
		ret
		nop
		nop
		nop
		nop
	}
}